1. Field of the Invention
The invention relates to an apparatus for attaching the front end of a boot to a longitudinal ski, particularly for use in cross-country skiing.
More particularly, it relates to an apparatus comprising a support adapted to be pivotably mounted around a transverse axis on a ski and to carry towards the rear, a retention apparatus of the front end of the boot. The attachment apparatus further comprises elastic bias means for rotation of the support around the longitudinal axis of the ski, in a predetermined direction for biasing movement of the support towards the rear and towards the bottom of the ski.
2. Description of Background and Relevant Materials
Apparatus of this type are known, and are described for example, in French Patent Application No. 2,447,73l and its corresponding U.S. Pat. Application Ser. Nos. 4,382,611 and 4,484,762 belonging to Applicant's assignee, particularly with reference to FIGS. 29 and 30 of the French document, the disclosures of which are hereby incorporated by reference thereto, and in French Patent Application No. 2,537,0ll belonging to Applicant's Assignee, particularly with reference to FIGS. 8 and 9 of the French document, the disclosure of which is hereby incorporated by reference thereto.
These known apparatus are provided with a mounting on the skis having a smooth upper longitudinal surface, on which a base plate is screwed down flat to define the transverse axis of rotation of the support with respect to the ski.
Cross-country skis are presently being developed whose upper surface has a longitudinal rib bordered by two longitudinal strips.
On such skis having ribs, the known apparatus described for example by the two documents noted above, can be mounted by means of a covering zone or compensation element covering the rib and the longitudinal strips of the upper surface situated respectively on both sides thereof. This compensation element having, towards the top, a smooth surface adapted to allow for the mounting of the base plate of the known apparatus. Alternatively, one can provide for shaping this base plate, towards the bottom, such that it mates with the rib and the longitudinal strips of the upper surface bordering it. In either embodiment, it is appropriate to modify the geometry of the retention apparatus of the front end of the boot on the support to permit variation of the seating of the boot on the ski.
Such adaptations of an apparatus of the known type are not completely satisfactory because they permit a lifting of the assembly of the apparatus with respect to the ski, particularly with respect to the longitudinal edges thereof. This increases the friction against the snow as well as the risks of accumulation of snow in front of the apparatus. Furthermore, this apparatus becomes more vulnerable to shocks, particularly in its front portions where the elastic bias means are generally located, resulting in increased risk of deterioration.